Ratchet wrenches often act as a fastening tool. When in use, a rotating component provided with ratchet on a circumferential side surface thereof, is connected to an end of a handle of the ratchet wrench, and one of the pair of locking claws/pawls guided in forward and reverse directions is selectively engaged with a ratchet wheel, to rotate the a fastening part in a forward direction or a reverse direction driven by the rotating component, directly or indirectly. And, a switching assembly connected to the locking claw performs the switching between the forward and reverse rotation directions (for example, as shown in Patent 1 and 2).
Patent 1: Patent Application Publication No. CN 102019595 A;
Patent 2: Patent Application Publication No. JP-A-2004-345011;
In the prior art, there are some defects as following:
(1) In the rotation of the handle to drive the rotating part, there are mainly two states: first, the handle rotates in the forward direction and the torque is transmitted to the rotating part; while in the reverse rotation, the rotating part slides relative to the handle; second, the handle rotates in the reverse direction and the torque is transmitted to the rotating part, while in the forward rotation, the rotating part slides relative to the handle, leading an idle state for the handle. However, in these states, the torque transmission between the handle and the rotating part in the forward and reverse directions cannot be cut at the same time. In some working conditions, a third state different from the first and second states is needed. Therefore, there are certain limitations when applying the traditional ratchet wrench in a variety of working conditions.
Of course, when the switching assembly controls the movement of the forward and reverse locking claws to a certain position, there may be cases where the forward and reverse locking claws disengage from the ratchet wheel at the same time, but this is not the original purpose of the switching operation, and that position is also unable to carry out accurate positioning and does not have normal working conditions;
(2) Each of the pair of locking claws needs to be controlled by one switching assembly to cooperate with the ratchet wheel to achieve the switching between the forward and reverse rotation directions, and it is inconvenience.